LAN over Electricity Wires

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sun.moon
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LAN over Electricity Wires

Post by sun.moon » Sat Oct 29, 2005 1:48 am

Edit by mod: Scroll down to a later post (with pictures) for the full review; this thread didn't orginally start out as a review.

Hi all,

I got a test package of a Devolo MicroLink dLAN ethernet set from a friend yesterday. Set it up this morning. Basically, its LAN over the home electricity wires in your house. You just stick the dLAN adapter into a normal power outlet, attach a LAN cable between your computer and the adapter, and walah! It’s really easy, no long cables, no wireless LAN to configure, and cool! 8) Home networking and Internet access is a breeze.

The test package is still the older version with only 14 Mbit/s. The new version has up to 85 Mbit/s. But still, downloads with this dLAN are almost twice as fast as with my WLAN 802.11g setup (two PCs, one Notebook). After testing this for a few days, I’ll probably switch out my WLAN for this dLAN technology.

Has anybody else tried this dLAN?

-sun.moon

Aris
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Post by Aris » Sat Oct 29, 2005 1:59 am

it sounds really interesting. if it works well it could save company's ALOT of money, since like 90% of the cost of networks is within the building. this was always one of the great selling points of Wireless LAN's.

i was actually thinking about using the electrical outlets in the house as attena's for getting radio stations recently. i thought mabey i could just use the grounding wire, but someone at work said that wouldnt work because it would ground out to earth ground and the signal would be lost before it got to the radio. but i think you could still do it on the electrical lines, you'd just have to find a way to isolate the actual power from it before it got to the radio.

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Post by Elixer » Sat Oct 29, 2005 2:43 am

Aris wrote: i was actually thinking about using the electrical outlets in the house as attena's for getting radio stations recently. i thought mabey i could just use the grounding wire, but someone at work said that wouldnt work because it would ground out to earth ground and the signal would be lost before it got to the radio. but i think you could still do it on the electrical lines, you'd just have to find a way to isolate the actual power from it before it got to the radio.
Devices that do this for TV radio have been made. Unfortunately they are generally less effective than a traditional indoor antenna. I don't see why doing this for FM radio would be any more effective as it is transmitted on frequencies close to TV. However, grounding one side of your antenna will generally increase reception, and is drawn in on many radio schematics.

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Post by Devonavar » Sat Oct 29, 2005 11:43 am

This is based on HomePlug technology, correct? I looked into doing this for my own home, but I shied away because of the cost. Would you mind doing a mini-review of this product, with photos, notes on installation, performance etc?

Also, if anybody is interested in a full-blooded SPCR review, I might be willing to consider finding a sample if there's enough interest....

sun.moon
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Post by sun.moon » Sat Oct 29, 2005 12:08 pm

Devonavar wrote:Would you mind doing a mini-review of this product, with photos, notes on installation, performance etc?
I'd be glad to do a mini-review - but it'll have to wait a few days. I'm leaving tomorrow for the north of Germany with my little girl - Tuesday is a holiday and I took Monday off work.

The mini-review would not be done from a "techie" point of view, but rather from an end-user who appreciates this technology viewpoint, if you know what I mean :)

In the meantime, if there is any other interest out there - please raise your hand...

sun.moon
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Post by sun.moon » Tue Nov 01, 2005 3:01 pm

This is a mini-review of the Devolo MicroLink dLAN Ethernet Kit as per Devonavar’s suggestion. First things first, I am in no way associated with Devolo :!: This is my first review, so only constructive criticism please :) Also, it appears that this technology has been readily available in retail channels to consumers for a couple of years now. It may not be new to everyone, but it certainly has not yet hit the mainstream (at least in Germany). In the event that you are already familiar with this, I don’t mean to bore you.

Devolo is a German company located in Aachen (former engineers of ELSA). They only distribute their products in Europe, but there are also companies in North America and elsewhere who produce and distribute HomePlug based products (see this link).

I first heard about this technology of LAN over home electricity wires about 8 years ago when the local internet provider in my town announced that they would be investigating this technology. I had indicated my interest that I'd like to be a pilot customer, but the project never got off the ground. I guess the technology wasn’t mature enough. Since then, I have not followed developments in this arena. But I had enough of cable-salad, and would have had to have laid some tricky cable after a move – so I got on the WLAN bandwagon. Here in Germany, homes are built with thick metal reinforced concrete floors and stone walls. Not an ideal environment for WLAN. Unfortunately I never even considered dLAN at that time – in the meantime it had totally escaped my attention.

A couple of weeks ago, I friend of mine mentioned in passing that he has had dLAN installed in his home for some time now. I looked at him like he was a horse. dLAN :?: What the heck is that :?: :?: After he told me, I was sold. I was able to get a test set of Devolo’s first version, which has a transfer rate up to 14Mbits/s. The newest Devolo version released has a transfer rate of up 85 Mbits/s. These transfer rates also depend on the electrical installation in your home – they are theoretical. My WLAN 802.11g has a theoretical transfer rate up to 54Mbits/s. Normally, my WLAN adapter client shows me a transfer rate of 6 to 24 Mbits/s (remember the thick concrete walls).

The Packaging:
Image


So, what is dLAN? “Direct” LAN, or dLAN (a trademark of Devolo) is the transfer of LAN traffic over home electrical wires. It is based on the “HomePlug” Concept. So when I refer to dLAN in this review, I actually mean the HomePlug technology. There are no cables to lie, nothing complicated to configure, and it’s easy and fast. Any two devices, e.g. PC, router, modem, gaming console, IP-TV, that are connected via a dedicated cable or wireless technology, are now connected with electrical wires in your home – just plug an adapter into a power outlet, plug a LAN cable into it, do the same on the other end, and your connected. The Devolo set has a really small and simple configuration utility. All you do is type in the Security ID of the Adapter you want to connect to, that’s it. Each adapter has its unique Secure ID number located on the sticker on the backside.

The Adapters:
Image


Now, on to my test. My home network consists of two PCs and one notebook attached to a router with 802.11g WLAN technology. A repeater is situated between one of the PCs and notebook, and the router. The router is attached to a DSL modem via an Ethernet cable.

Image


Since I only had two dLAN adapters, my testing was somewhat limited. First I tested the internet connection between PC1 and the router. For this setup I didn’t need to install the configuration utility. One adapter attached to PC1, the other attached to the router, and I was surfing, it was really as simple as that. I achieved downloads up to twice as fast as with my WLAN setup. I tested a download of the WINAMP client. With my WLAN setup I had a max transfer rate of 110 KB/s, 5 Minutes later, from the same URL, I had 225 KB/s with dLAN. For the sake of accuracy I repeated this test and had the same results. The Devolo utility showed me that my connection rate was 9 Mbit/s. The WLAN connection rate was “apparently” 20 Mbit/s. I don’t understand why the dLAN download was so much faster, but it was.

Then I wanted to test the connection between two PCs. I attached the dLAN adapter to PC2. In order for PC1 and PC2 to recognize each other, I needed to install a small configuration utility. All this utility asked of me was to insert the Security ID number of the adapter I wanted to connect to on the other PC and visa versa. According to the Devolo utility, I realized a transfer rate of 6Mbit/s between the two PCs. Nevertheless, with the dLAN connection I also encountered faster transfer rates than with the WLAN connection. Also, when I moved through directories on the networked PC, the directories opened up and displayed the contents as if they were local. When I move through directories on the networked PC with the WLAN connection, I suffer with an hourglass after each click. The dLAN connection is just snappier.

Plugged in:
Image


Keeping in mind, I was testing the first version of Devolo’s product with up to 14 Mbit/s, I wonder what the newest release will be like with 85 Mbit/s.

There is quite a bit of information on the web. Here is one short review of the Devolo product I found in English. Devolo also has other interesting products based on this technology such as the transfer of audio and USB signals over home electricity wires (really, I am not associated with Devolo!) :)

Prices: According to geizhals, the 14Mbit/s dLAN Ethernet starter kit (incl. two adapters) runs around 75 Euro in Germany. The high speed version runs around 145 Euro. That is reasonable enough for me, especially when I consider, that I could unload three WLAN adapters, a repeater and a WLAN router in Ebay.

Conclusion: I am convinced that this technology is the way to go for me. It is utterly simple to set up, reduces cable work and configuration and is fast. No matter where I want to move a PC in the house, I am connected.

So, for those of you who are interested, maybe this mini-review whetted enough appetites for Devonavar to perform a full scale review. We’ll see! I know I’d like to read it :)


p.s. I was uncertain if I should post this in the User Review forum. If a moderator feels it should be moved, please do so. Thanks.


EDIT: for some reason I had to relink the pictures (??)
Last edited by sun.moon on Fri Nov 04, 2005 4:28 pm, edited 2 times in total.

perplex
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Post by perplex » Tue Nov 01, 2005 6:04 pm

wow LAN over electric cables. that sounds crazy. does it work well then?

surely you cant connect in another building though? would the reason be that the signal would be too weak?

Beyonder
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Post by Beyonder » Thu Nov 03, 2005 10:09 am

I work a lot with powerline networking at my company; we're going to be releasing a product that networks over the powerlines in your house using the homeplug stuff.

Anyways, I'm not a marketing guy, so.....no sales here. :P


My impression of powerline network:
  1. Definitely a "dirty" network. That being said, so are 802.11x networks. They're dirty in the sense that they can degrade, suffer high levels of packet loss, and be advsersely affected by external factors. Common problem points for powerline networking include PCs without APFC (spcr.com should make greater note of this--having "clean" power in your house can be pretty important), friges, dryers, power tools, etc. Typically things that dump a lot of muck onto the powerline, which don't represent a simple resistive load (i.e: toaster).
  2. Data rates on 14 mbps powerline networks are exaggerated, but so are all specified data rates for every networking medium I've ever encounered. The realistic transfer rate on powerline (and I've personally tested this with networking code I've written, using both UDP and TCP) is more around 6-7 mbps, depending upon the quality of the connection. Poor connections degrade to less than 1 mbps. That being said, it's better than what I get with 802.11b. I have not tested the 85 mbps product, but I'd imagine it'll get about 40-50% of that figure under ideal conditions. 802.11 derivatives seem to get even less than this, in my experience.
  3. Powerline is better at traversing a house than 802.11x derivatives.
  4. If you want a "good" network, just get gigabit. ;) Although I like powerline and 802, they're both trashy, dirty, latent, lossy networks. Businesses and people who need network performance should look elsewhere.
Personally, I'm hoping that people will eventually have both types of network in their house--there's a big advantage in my mind to having separate networks for different things. What I really want someone to do with powerline is make a small, cheap module that can be added to any appliance (less than $5 to manufacture) that provides a powerline networking interface and enough processing power to do basic logic. Then you could incorporate that into any number of devices for use in home automation, using standard TCP/IP based protocols.


Anyways, blah blah.

sun.moon
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Post by sun.moon » Fri Nov 04, 2005 4:49 pm

Thanks Beyonder, for sharing your views and opinions.

You are right, this is a dirty network in that respect, but nevertheless considerably faster than the WLAN setup I have. From what I understand, one reason the dLAN is faster, is that WLAN needs to verify the address for each package that is sent over the network, and dLAN sends the packages in bulk. (Maybe I got this wrong, I'm not a network expert).

I've tested some more large file transfers between PCs, and there is just no question about the speed. My friend does streaming video, data backups and network gaming over his dLAN network and has never encountered problems. He will also move to to the 85 Mbit/s version. For business or high reliabilty use it is probably not ideal, but for typical home use it's seems to be more than sufficient. I have to give the test set back next week. I've decided to migrate my network to dLAN.

Annotation: Of course gigabit is really the best, cleanest and fastest LAN, but then I have to lay cables again between rooms and floors. I have no desire to do that. :)

Beyonder
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Post by Beyonder » Thu Nov 10, 2005 11:09 am

I agree: gigabit requires running cable, which is decidedly less trivial than powerline or 802.11 networking. Still, if I ever get a house, it's going to have gigabit because I'm obsessive like that. :D

I know there's some 200 mbit/sec powerline stuff that's either out or is going to be coming out. Not sure what the status of that is, though. That'd make a pretty nice (and speedy) home network.

sgent
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Wirless

Post by sgent » Thu Nov 10, 2005 1:10 pm

A little OT, but I have noticed a significant difference in speed depending on hardware for 802.11b.

I plug in my linksys stuff and get 5-6Mbits max, but if I plug in my Cisco Aironet stuff from work, I can usually hit 100Mbits from a much larger range. I'm not sure why the difference, but components in my experience make a difference.

aqm consultant
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Post by aqm consultant » Thu Nov 10, 2005 1:13 pm

This could have saved me alot of hours and several hundred feet of CAT5! What about network security? Is it possible for someone in a neighboring home/apartment to plug in an adapter and be behind your firewall? :(

Beyonder
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Post by Beyonder » Fri Nov 11, 2005 7:21 pm

aqm consultant wrote:This could have saved me alot of hours and several hundred feet of CAT5! What about network security? Is it possible for someone in a neighboring home/apartment to plug in an adapter and be behind your firewall? :(
Actually, no--that's one of the best things about powerline stuff. It has built in encryption. You set all devices to a password (default is typically something like "Homeplug" or vender name), and your traffic is isolated from other powerline networks on the same segment.

Beyonder
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Re: Wirless

Post by Beyonder » Fri Nov 11, 2005 7:22 pm

sgent wrote:A little OT, but I have noticed a significant difference in speed depending on hardware for 802.11b.

I plug in my linksys stuff and get 5-6Mbits max, but if I plug in my Cisco Aironet stuff from work, I can usually hit 100Mbits from a much larger range. I'm not sure why the difference, but components in my experience make a difference.
802.11b doesn't support 100 mb/sec--it must be 802.11g or some other wireless protocol. 802.11b officially supports 11 mb/sec, although the realistic transfer rate is probably one-half to one-third that number at best.

sun.moon
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Post by sun.moon » Fri Nov 11, 2005 11:38 pm

Beyonder wrote:It has built in encryption. You set all devices to a password (default is typically something like "Homeplug" or vender name), and your traffic is isolated from other powerline networks on the same segment.
Not only that, but I couldn't even see the other adapter in the network until I knew it's Secure ID number and entered that into the local client SW - and vice versa.



This underlines Beyonder's statement: "FAQ" from Develo Site
Question:
How safe is the 56Bit encryption?

Answer:
To decrypt the data you have to attain the encrypted row data. But this fact will be prevented due to the HomePlug compatible hardware. The chip does not directly forward encrypted data to the host interface, only each key in the chip can be decrypted. Due to the diversity of keys and a transmission rate between computer and chip of 100 Mbps it would take about 45000 years.

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Post by HammerSandwich » Fri Nov 18, 2005 10:26 pm

Devolo's FAQ confirms my fear: the dLAN adapter shouldn't be plugged into a surge suppressor, because the noise filters attenuate the data signal. The technology may be convenient, but don't forget this serious drawback.

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Post by wainwra » Fri Nov 18, 2005 11:25 pm

I'd heard a lot about this while I was in England, and had alwasy thought - bit gimmicky; why bother with this, when you can have a much better wired network?

But then I moved to Germany. I'm living in a (lovely) rented house, with concrete and marble everywhere. There ARE wiring ducts, but I'm afraid I filled those very quickly with telephone and television wires. There are some places I simply can't get any more cables. I have had wiring people come in to take a look, and they have concluded that short of ripping everything out and starting all over (very big expense), there's nothing that can be done.

To give you just one of the three problems I have:

I have a wifi router in the top floor of the house. Because of the construction of the house (these things are STURDY! They don't build with wood here) The signal only goes down one floor. I can pick up the signal again in the garden, but not down in the lounge, which is a shame. To get wifi throughout the house, I'd have to move the wifi router, and the cabling just doesn't permit that.

It's clear to me from reading this post now that this is my (only) solution! Thank you very much!

Beyonder
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Post by Beyonder » Sun Nov 20, 2005 11:14 pm

HammerSandwich wrote:Devolo's FAQ confirms my fear: the dLAN adapter shouldn't be plugged into a surge suppressor, because the noise filters attenuate the data signal. The technology may be convenient, but don't forget this serious drawback.
This is true--it also doesn't function as well going through UPS. Generally, any sort of surge protector or large capacitive load doesn't allow the signal through as well (UPS is really harsh). That being said, I've managed to get a decent signal through two hundred feet of extension cord and a UPS--the powerline just drops the datarate accordingly when powerline conditions become less than favorable.

sun.moon
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Post by sun.moon » Wed Nov 23, 2005 5:17 am

HammerSandwich wrote:Devolo's FAQ confirms my fear: the dLAN adapter shouldn't be plugged into a surge suppressor, because the noise filters attenuate the data signal. The technology may be convenient, but don't forget this serious drawback.
Not being the electrician expert, what does that mean exactly? That the signal strength is weaker when plugged into a surge suppressor, or the signal quality is deteriorated? Is there a risk with a lightning strike sending a surge through the LAN cable? (Please don't laugh if my questions appear silly...).

I can only say that I impressed with the performance compared to WLAN. But if there are inherent risks using powerline LAN which could damage data or my system, I'd surely like to know!

Thanks

Beyonder
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Post by Beyonder » Mon Jun 04, 2007 7:38 am

sun.moon wrote:
HammerSandwich wrote:Devolo's FAQ confirms my fear: the dLAN adapter shouldn't be plugged into a surge suppressor, because the noise filters attenuate the data signal. The technology may be convenient, but don't forget this serious drawback.
Not being the electrician expert, what does that mean exactly? That the signal strength is weaker when plugged into a surge suppressor, or the signal quality is deteriorated? Is there a risk with a lightning strike sending a surge through the LAN cable? (Please don't laugh if my questions appear silly...).
This is a pretty late reply, but:

There isn't any risk in lightning strikes or power surges; the issue is simply one of performance. When you plug in a powerline module to a UPS or surge protecter, it attenuates the data signal, which is a fancy way of stating that you might have decreased throughput and/or increased packet loss.

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Post by mellon » Mon Jun 04, 2007 10:27 am

Beyonder wrote:
aqm consultant wrote:This could have saved me alot of hours and several hundred feet of CAT5! What about network security? Is it possible for someone in a neighboring home/apartment to plug in an adapter and be behind your firewall? :(
Actually, no--that's one of the best things about powerline stuff. It has built in encryption. You set all devices to a password (default is typically something like "Homeplug" or vender name), and your traffic is isolated from other powerline networks on the same segment.
I still have to wonder if the security model is strong enough. Without any knowledge of the matter it sounds like this traffic encryption is created by the vendor and is thus vendor specific and not generally peer-reviewed.

I'd be quite surprised if the network security was actually any better than the easily-crackable WEP for WLAN. And WEP was actually part of the IEEE 802.11 standard. As with WEP the security may hold while only the early adopters are using the system but once the massed get hold of it some bright guy decides to break the encryption and suddenly the network traffic is totally open.

A really insidious neighbour might even record all the encrypted network traffic for later use when some easy-to-use cracking tool comes generally available ;)

Overall, vendor-specific non-open security is usually bad.

Beyonder
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Post by Beyonder » Thu Jun 07, 2007 4:24 pm

mellon wrote: I still have to wonder if the security model is strong enough. Without any knowledge of the matter it sounds like this traffic encryption is created by the vendor and is thus vendor specific and not generally peer-reviewed.
In the case of Homeplug, it uses triple DES encryption. There are more recent algorithms that are better, but it's far from being vendor specific or unreviewed. It's also still secure; there are several brute force solutions, none of which will be feasible for a long, long time.
I'd be quite surprised if the network security was actually any better than the easily-crackable WEP for WLAN. And WEP was actually part of the IEEE 802.11 standard. As with WEP the security may hold while only the early adopters are using the system but once the massed get hold of it some bright guy decides to break the encryption and suddenly the network traffic is totally open.;)
It's much more secure than WEP, which is an outdated standard anyways. That said, it's perfectly fine for a lot of home networks. I don't actually use security on my network other than MAC address filters, because there just isn't a point. Traffic that needs to be secure goes over SSL anyways, and I've seen my neighbors: they're not that smart.
Overall, vendor-specific non-open security is usually bad.
...which is why Homeplug is neither.

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Post by quikkie » Wed Jun 20, 2007 2:13 am

I have a set of the 85Mbit versions between my adsl router ("upto 8MBit" connection to the internet) and my "office" and while I haven't done any speed tests I am doing all the things you shouldn't do* and still get a "fast enough" signal - meaning that my access to the internet isn't restricted by the dLAN adapters.

*The instructions specifically state that you shouldn't connect the adapters to a surge protector or try and use the adapters on different electrical circuits. I'm in a recently built house, using surge protected 4-way extensions on both ends and the signal goes through the fuse box to go from the ground level to first floor.

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